Flap seal

ABSTRACT

The invention relates to a flap seal in the form of a lamella seal, comprising at least three essentially flat individual rings ( 1, 10 ) lying one on top of another in a bundle-type form. Said individual rings ( 1, 10 ) comprise an inner-part which is respectively defined by an inner circumferential surface (2, 11). The outer-lying individual rings (1) are covering rings, and the inner-lying individual rings ( 10 ) are sealing rings. High-quality sealing surfaces can be produced by allocating positioning means to the covering rings ( 1 ) for positioning said covering rings ( 1 ) in relation to one another in the circumferential direction and/or in relation to the inner-lying sealing rings ( 10 ) in the radial direction. The positioning means also enable a relative movement in the axial direction.

[0001] The present invention relates to a flap seal of the type for alamella seal having the features of the introductory portion of claim 1.

[0002] Flap seals of this type are known in the practice and aredeployed, for example, with throttle valves in steam conduits.

[0003] A seal of this type is disclosed, for example, in DE 298 22 791U1. The flap seal shown therein includes two cover rings which surrounda packet of sealing rings. This flap seal is formed by initiallyassembling together annular discs in a packet-type manner. The metallicrings include on the inner sides thereof inwardly oriented noses which,upon mounting of the disc packets, together under axial pressure, arewelded to one another and the flap seal is thus permanently securedtogether. After this welding, the flap seal is brought by cutting orshaving into its designated form, which corresponds to the sleevesurface of a conical section of an inclined or tapered cone.

[0004] Otherwise, it is known in connection with conventional flap sealsto assemble these together as well prior to the cutting or shaving work,with the individual lamellae being adhered to one another.

[0005] It is problematic in connection with these flap seals that theycan no longer be divided or separated from one another after the cuttingor shaving work. For this reason, the cover discs, which are typicallyformed of metal, and the sealing discs disposed therebetween, cannot bede-burred separately from one another. The de-burring of the fixedpackets of discs comprised of materials which typically differ from oneanother therefore does not lead to an optimal surface quality of theseal surface.

[0006] It is, therefore, the object of the present invention to create aflap seal the individual discs of which can be collectively worked orhandled while the individual discs are securely mounted to one another,the individual discs of which can, further, be separated from oneanother for de-burring work thereon as desired and, following thede-burring, can be assembled together again in substantially theoriginal orientation.

[0007] This objective is realized by a flap seal having the features ofclaim 1. An inventive method for finishing or preparing a flap seal isset forth in claim 10.

[0008] Due to the arrangement of positioning means relative to the coverrings, which position the cover rings relative to one another in thecircumferential direction and/or relative to the inwardly disposed sealrings in a radial direction and which permit relative movement of thecover rings in the axial direction, the rings can be assembled togetherin the designated orientation, axially pressed, and then worked on inthe assembled condition. They can then be again separated in the axialdirection. The rings can then be de-burred and again assembled togetherin the original orientation. The pressing of the flap seal in the valveduring the mounting step occurs, as well, in the axial direction.

[0009] Advantageous embodiments of the invention are set forth in thedependent claims. In view of the fact that, in connection with theinventive method, there initially occurs a stacking of the individualrings in the designated serial arrangement, whereby the individual ringsare releasably fixedly secured to one another radially and in thecircumferential direction, then the finishing of the outer contour viacutting or shaving work, the thereafter-following separation of theindividual rings, the de-burring of the individual rings, to the extentrequired, and, eventually, the assembling together of the individualrings in the original orientation and serial arrangement, as well as amounting of the individual rings under axial pressure, a flap seal isproduced whose individual rings have been finished or worked in apredetermined manner. The mounting then follows again in the arrangementby which the designated contour is ensured. The configuration of theworked surfaces of the individual rings is substantially improved incomparison to that effected by the known processes.

[0010] There follows hereinafter a description of an embodiment of thepresent invention with reference to the figures of the drawing.

[0011] The figures of the drawings show:

[0012]FIG. 1: A cover ring of an inventive flap seal shown in an axialplan view thereof;

[0013]FIG. 2: The cover ring shown in FIG. 1 in a sectional side viewthereof;

[0014]FIG. 3: A seal ring shown in a top plan view, as well as

[0015]FIG. 4: An inventive flap seal shown in a side sectional view.

[0016] As seen in FIG. 1, a cover ring 1 of an inventive flap seal isshown in an axial plan view. The cover ring 1, as is the case with othertypical individual rings of a flap seal, is substantially annularlyshaped before it is subjected to working. Individual clips 3 areprovided as positioning means on an inner circumferential surface 2 ofthe cover ring 1,. The clips 3 are, in this connection, comprised offour positioning means, each disposed at respective positions around thecircumferential direction 90 degrees offset from one another. In thisconnection, two of the offset positions, which are offset to one anotherby 180 degrees, are provided with a clip in the form of a nose-shapedpositioning means 5, while the other two offset positions, which liebetween the nose-shaped positioning means 5, have respective clipsdisposed thereat in the form of fork-shaped positioning means 6. Theindividual clips 3 of the fork-shaped positioning means 6 are disposedat a spacing from one another which corresponds to the width of anose-shaped positioning means 5. The clips 3 are bent at an angle ofapproximately 90 degrees relative to the plane of the cover ring 1 inthe axial direction and extend to one side of the plane of the coverring 1.

[0017] Continuing, on the inner circumferential surface, an index marker7 is disposed between a nose-shaped positioning means 5 and afork-shaped positioning means 6.

[0018]FIG. 2 shows the cover ring 1 shown in FIG. 1 in a side sectionalview thereof. It can be seen that the clips 3 are formed as individuallyformed material portions bent downwardly from the plane of the coverring 1.

[0019]FIG. 3 shows a seal ring 10 in a plan view thereof along the axialdirection, corresponding to the illustration shown in FIG. 1. The sealring 10 is, as well, annularly shaped before the working thereof andcomprises an inner circumferential surface 11, having a respectivecutout 12 formed at each respective one of four positions disposed at 90degree offsets from another. The cutouts 12 are dimensioned to the fullaxial height of the inner circumferential surface 11 and extend in thecircumferential direction to a respective width which corresponds to theouter dimension of a fork-shaped positioning means 6.

[0020]FIG. 4, consequently, shows a finished or completely worked flapdisc seal with an upper cover ring 1 and a lower cover ring 1, as wellas a seal ring 10 disposed therebetween. The outer circumferentialsurface of the flap seal is configured via cutting or shaving work incorrespondence with the configuration of a conical section of aninclined or tapered circular cone.

[0021] The preparation of the flap seal as shown in FIG. 4 comprisingthe components shown in FIGS. 1-3, is effected in the following manner:

[0022] Initially, two identical cover rings 1 are prepared from suitablesheet metal, such as, for example, via laser cutting. The clips 3 arebent out to one side of the plane of the cover ring 1. The seal ring 10is formed out of a suitable material in a similar manner. The materialcan, in this connection, be a halogenated plastic, graphite, or can be,as well, metal. A plurality of seal rings 10 can also be deployed.

[0023] Now the seal ring 10 is engaged on both sides by respective coverrings 1 and, indeed, in a manner such that the markings 7 of the twocover rings 1 coincide with one another in the axial direction. Theclips 3 of the cover rings 1 face one another. Via this orientation, thenose-shaped positioning means 5 are received in the in-between spaces ofthe fork-shaped means 6. The fork-shaped positioning means 6 aredisposed in the cutouts 12 of the seal ring 10. In this manner, bothcover rings 1, as well as the seal ring 10, are secured against turningmovement and displacement movement in the plane of the ring. Thearrangement remains, however, axially compressible.

[0024] The packet is now pressed in a suitable apparatus and subjectedto working such that the conventional outer contour, as shown in FIG. 4,is produced. Now, the individual rings can be again taken apart from oneanother and the worked outer side can be de-burred, such that a desiredtop surface quality is achieved. due to the unique fixed securement ofthe flap seal via the positioning means 5, 6 and the cutouts 12, there-assembly together of the cover rings 1 and the seal ring 10 leads tothe flap seal being assembled together in the same orientation as it hadas it was subjected to working. Thereafter, the assembled packet can bemounted in a conventional mounting of a flap seal valve via axialpressing.

[0025] The assembly comprises in its entirety a flap seal which providesa substantially improved top surface quality with relatively simpleworking.

[0026] In contrast to the heretofore known flap seals, the inventiveflap seal provides the further advantage that the individual rings nolonger need be adhered to one another or welded to one another. Thiswork step can be omitted. In contrast to flap seals formed by adhesion,the further advantage is obtained with the inventive flap seal that, forthe first time, PTFE-comprising seal rings, which cannot be adhered toone another, can be used. It is additionally possible to finish theouter contours of the cover rings slightly smaller than the seal ring.In this manner, it can be avoided that the valve seat comes into contactwith the cover rings and eventually prematurely wears away the coverrings.

[0027] These significant advantages are provided not only in connectionwith the illustrated arrangement of two cover rings I and a seal ring10. Rather, seal rings comprising alternating graphite and metal ringsor a large number of graphite rings can also be deployed. It is alsopossible to deploy a plurality of seal rings 10, which are collectivelyformed of metal. The separate follow-on work possibilities permit, aswell, a high level of quality of the subsequently formed seal surfaces.

[0028] In addition to the afore-described embodiments, the seal ring canalso comprise an inner circumferential surface which deviates from theafore-described sleeve surface of an annular cylinder. Thus, forexample, the inner cutout delimited by the seal ring can have multipleangles and, especially, can have a quadratic shape.

1. Flap seal of the construction type of a lamella seal comprised of atleast three packet-type, substantially planar individual rings (1, 10)stacked upon one another, whereby the individual rings (1, 10) eachcomprise an inner cutout which is respectively delimited by an innercircumferential surface (2, 11), and whereby the outwardly disposedindividual rings (1) are cover rings and the inwardly disposedindividual rings (10) are seal rings, characterized in that, positioningmeans (3) are disposed to position the cover rings (1) relative to oneanother in the circumferential direction and/or relative to the inwardlydisposed seal rings (10) in a radial direction and which permit relativemovement of the rings in the axial direction.
 2. Flap seal according toclaim 1, characterized in that, the cover rings (1) include clips (3)arranged in the region of the inner circumferential surfaces (11), theclips extending outwardly from the plane of the cover rings.
 3. Flapseal according to one of the foregoing claims, characterized in that,the clips (3) are configured as fork-shaped (6) and nose-shaped (7)positioning means.
 4. Flap seal, according to one of the foregoingclaims, characterized in that, the fork-shaped and nose-shapedpositioning means (6, 7) are arranged in alternating manner in thecircumferential direction of the inner circumferential surface (11). 5.Flap seal, according to one of the foregoing claims, characterized inthat, both cover rings (1) are identically configured and are arrangedwith their positioning means (3) in opposition to one another in theflap seal, whereby the nose-shaped positioning means (5) of a cover ring(1) is received in a respective one of the fork-shaped positioning means(6) of the opposed cover ring (1) such that a form locking is effectedin the circumferential direction.
 6. Flap seal, according to one of theforegoing claims, characterized in that, the positioning means (3) isdisposed on the inner circumferential surface (12) of at least one ofthe inwardly disposed seal rings (10) so that the seal ring (10) issecured relative to the cover rings in the radial direction.
 7. Flapseal, according to one of the foregoing claims, characterized in that,both cover rings (1) are in contact via their positioning means (3) atat least three locations with the inner circumferential surface (11) ofat least one of the inner seal rings (10).
 8. Flap seal, according toone of the foregoing claims, characterized in that, the innercircumferential surface (11) of the inner seal ring (10) comprisescutouts (12), in which the positioning means (3) are received and whichfix the seal ring (10) in the circumferential direction relative to bothcover rings (1).
 9. Flap seal, according to one of the foregoing claims,characterized in that, at least one of the inwardly disposed seal rings(10) is formed of a plastic material, especially a PTFE-comprisingplastic, or graphite.
 10. A method for producing a packet-type flap sealcomprising individual rings, characterized in that the following stepsare provided: stacking the individual rings in a designated serialarrangement, whereby the individual rings are releasably fixedly securedto one another radially and in the circumferential direction; finishingthe outer contour via cutting or shaving work; separating the individualrings; de-burring the individual rings, to the extent required;assembling together the individual rings in the original orientation andserial arrangement; mounting the flap seal under axial pressure.